Jul 22 – 26, 2019
Europe/Rome timezone

Development of superconducting tunnel junction detector with cryogenic amplifier for COBAND experiment.

Jul 25, 2019, 5:45 PM
1h 15m
Piazza Città di Lombardia (Milano)

Piazza Città di Lombardia


Piazza Città di Lombardia, 1, 20124 Milano MI
Poster Detector readout, signal processing, and related technologies Poster session


Mr Akihiro Kasajima (University of Tsukuba)


The purpose of COBAND (COsmic BAckground Neutrino Decay) experiment is to determine neutrino mass by measuring neutrino decay photon. Expected neutrino decay photon energy is too small (25 meV) to detect using a semiconductor detector,so we adopted the STJ (Superconducting tunnel Junction) detector using superconductor which has much smaller energy gap than a semiconductor. Our Nb/Al-STJ prototype already satisfied our demands to detect a far-Infrared single photon, but the large noise of readout line inside of refrigerator prevent the detection. For that reason we consider amplifying the STJ's signal by cryogenic amplifier near STJs. We require that the cryogenic amplifier can be operated at lower than 3 K, can amplify fast signal from STJ (<$\rm 10 \mu s$), has low noise (NEP ~$\rm 1×10^{-19} {W/ \sqrt{Hz}}$), and has lower power consumption than the refrigerator cooling capability. Cryogenic amplifier consists of FD-SOI-MOSFET known to operate at cryogenic temperature. The present prototype of a cryogenic amplifier is a charge integrating amplifier with negative feedback. It is composed of an amplification stage and a buffer amplifier. We confirmed that this amplifier worked at cryogenic temperature 350 mK and measured its gain and equivalent input noise charge. I will report the result of amplification with this cryogenic amplifier of Nb/Al-STJ signals by illuminating visible laser pulse.

Less than 5 years of experience since completion of Ph.D N
Student (Ph.D., M.Sc. or B.Sc.) Y

Primary author

Mr Akihiro Kasajima (University of Tsukuba)


Prof. Shin-Hong Kim (University of Tsukuba) Dr Yuji Takeuchi (University of Tsukuba ) Dr Takashi Iida (University of Tsukuba) Dr Kenichi Takemasa (University of Tsukuba) Ms Chisa Asano Dr Takehiro Wada (JAXA/ISAS) Dr Koichi Nagase (JAXA/ISAS) Prof. Shuji Mastuura (Kwansei gakuin University) Prof. Yasuo Arai (KEK) Prof. Ikuo Kurachi (KEK) Prof. Masashi Hazumi (KEK) Prof. Takuo Yoshida (University of Fukui) Dr Satoshi Mima (RIKEN) Dr Kenji Kiuci (University of Tokyo) Prof. Hirokazu Ishino (Okayama University) Dr Atsuko Kibayashi (Okayama University) Prof. Yukihiro Kato (Kindai University) Dr go Fujii (AIST) Dr Masahiro Ukibe (AIST) Dr Shigetomo Shiki (AIST) Dr Masataka Ohkubo (AIST) Prof. Shoji Kawahito (Shizuoka University) Dr Erik Ramberg (Fermilab) Dr Paul Rubinov (Fermilab) Dr Dmitri Sergatskov (Fermilab) Prof. Soo-Bong Kim (Seoul National University) Prof. Yong-Ham Kim (IBS) Dr Hyejin Lee (IBS)

Presentation materials